What Is an Aneurysm?

Medically Reviewed by Zilpah Sheikh, MD on September 13, 2024
7 min read

As aneurysm is a bulge in the wall of one of your arteries. It happens when the pressure of blood passing through has forced a weakened part of the artery to balloon outward. Sometimes your blood vessel wall may have gotten weak for a different reason.

Aneurysms can happen in any blood vessel, but they usually form in the belly or chest portions of your aorta -- the main blood vessel that carries blood from your heart -- or in arteries that nourish your brain.

Aneurysms there are serious, while those in other areas, such as your leg, can be less hazardous.

The most serious threat of an aneurysm is that it will burst and cause a stroke or massive bleeding, which can be life-threatening. A large aneurysm can affect your circulation and lead to blood clots.

It's important to get aneurysms diagnosed and treated early. Aneurysms often have mild symptoms or none at all, so routine exams can help your doctor check for warning signs or risk factors.

 

 

Aneurysms can form in your heart, belly, brain, legs, or other internal organs. Aneurysm types are named for the arteries in which they form.

Aortic aneurysm. As the name suggests, this type happens in your aorta. It can be linked with hardening of the arteries, also known as atherosclerosis. It may be an inherited condition or a complication of high blood pressure or smoking.

Cerebral aneurysm. These happen in your brain. The most common type, known as a berry aneurysm, forms as a sac of blood that looks like a berry. 

Abdominal aortic aneurysm (AAA). This type of aneurysm forms where your aorta, the largest artery in your body, sends blood to your belly.

Thoracic aortic aneurysm. This type happens less often than an AAA. They form in your upper aorta in your chest.

Carotid aneurysm. These form in your carotid arteries, which bring blood to your brain, neck, and face.

Popliteal artery. One of the more common peripheral vascular aneurysms, it is a bulging or weakness in the wall of the artery that supplies blood to the knee joint, calf, and thigh. 

Mesenteric artery aneurysm. These aneurysms form in the artery that takes blood to your intestines.

Splenic artery aneurysm. This type of aneurysm forms in an artery in your spleen.

Ventricular aneurysm. This is a bulge in the wall of your heart. A previous heart attack is the most common cause. In rare cases, a severe chest injury can also lead to it.

Any condition that causes your artery walls to weaken can bring one on. The most common culprits are atherosclerosis and high blood pressure.

Deep wounds and infections can also lead to an aneurysm. Or you may be born with weakness in one of your artery walls.

If you have an aneurysm, you often may not know why it happened. It could be related to:

  • Buildup of fat and other substances in your arteries (atherosclerosis)
  • Family history
  • High blood pressure
  • Aortic injury
  • High cholesterol
  • Drug use
  • Smoking cigarettes
  • Pregnancy

Some inherited disorders also may increase your risk for an aneurysm including:

  • Fibromuscular dysplasia
  • Polycystic kidney disease
  • Coarctation of the aorta
  • Cerebral arteriovenous malformation

The symptoms that come with an aneurysm will depend on where it is in your body. Often, you may not notice anything at all. 

When an aneurysm in your brain grows without rupturing, you could have:

  • Double vision
  • Dizziness
  • Headaches
  • Ringing in your ears

The worst symptoms happen if an aneurysm ruptures or bursts. Symptoms of a ruptured aneurysm include:

  • Pain
  • Low blood pressure
  • Rapid heart rate
  • Feeling lightheaded

When an aneurysm in your brain ruptures you may have:

  • Severe headache
  • Neurologic injury
  • Coma
  • Death

If you have symptoms you think may be due to a ruptured aneurysm, including a sudden and severe headache, it's a medical emergency. Call 911 or rush to the emergency room.

Leaking aneurysm

You may have an aneurysm that leaks a little bit of blood without rupturing. This is also called a sentinel bleed. A leaking aneurysm may not have symptoms. Some people may get a warning headache.

To diagnose an aneurysm, your doctor will ask you questions, including whether another member of your family has had one. Then, they’ll give you a complete exam, during which they’ll:

If your doctor thinks you have an aneurysm in your aorta, the main artery in your body, you may get an ultrasound test. This is painless and can pinpoint and measure an aneurysm. If they think one is in your chest, you might get a CT scan.

If your doctor is concerned that you have one in your brain, you may get a CT scan or an invasive test called an angiogram. During this, dye is injected into an artery in an arm or leg and travels to your brain. A picture of your brain is then taken. The dye will make it easier for your doctor to see any problems.

An MRI can also check your aorta or blood vessels in your brain.

The only way to treat an aneurysm that's large and at risk of rupturing is to have it repaired with open surgery or an endovascular procedure.

Sometimes, surgery isn’t possible, or it may pose more danger than the aneurysm. Careful monitoring and medication may be best in that case. Medications can help by:

  • Improving blood flow
  • Lowering blood pressure
  • Lowering cholesterol

Your doctor will consider the size, type, and location of the aneurysm to help determine your best treatment course.

Surgeries to strengthen arteries or make a rupture less likely include:

Endovascular aneurysm repair. Your surgeon will inert a catheter into your vessel and use a graft to repair or strengthen your artery. 

Open surgery. Your surgeon will insert a graft or remove an aneurysm through a larger incision.

Endovascular coiling. Your surgeon will insert multiple coils through a catheter to pack the aneurysm and keep blood from flowing to it.

Microvascular clipping. Your surgeon places a metal clip at the base of the aneurysm to keep blood from flowing to it.

Catheter embolization. This procedure cuts off blood flow to the aneurysm to make a rupture less likely. They'll use a tube to deliver medications or other agents that prevent bleeding.

For inoperable aneurysms, you may be prescribed drugs to lower your blood pressure or ease the force of your heart's beating. Your chance of it bursting will go down.

Even for an operable aneurysm, your doctor may first try medication and a wait-and-see approach, monitoring its growth.

You may need surgery if your doctor finds that the aneurysm has become big enough to be dangerous. 

You can't always prevent an aneurysm from happening. The most important thing you can do to prevent aneurysms is to control your blood pressure.

Especially if you have a family history of stroke or heart disease, make changes in your diet and lifestyle to improve your health. Anyone can reduce their risk of an aneurysm by following these steps:

  • Exercise regularly.
  • Watch what you eat.
  • Eat heart-healthy foods, including fruits, vegetables, and plenty of fiber.
  • If you smoke, stop.
  • Stick to a healthy weight.
  • Watch your cholesterol levels and take steps to lower them if they're high.

See your doctor regularly for wellness checks to look for any risk factors you may have so you can take steps to lower your risks. If you already have an aneurysm, talk to your doctor about steps you can take to make a rupture less likely.

 

Aneurysms are bulges in the walls of your arteries that can rupture to cause serious symptoms or even death. There's no foolproof way to prevent them, but a healthy lifestyle can make an aneurysm less likely. If you have an aneurysm, talk to your doctor about steps to prevent it from rupturing, including surgery.

Can anything trigger an aneurysm?

High blood pressure is the most common reason aneurysms rupture. You may also trigger a rupture if you have ongoing stress or an angry outburst. Straining to lift heavy objects could make a rupture more likely, too.

Is it possible to survive an aneurysm?

Yes, it's possible. Aneurysms that aren't ruptured often don't cause any symptoms. You can live a long time with this type of aneurysm and not even know it. If you have a ruptured aneurysm, it can be fatal. About 75% of people with a ruptured brain aneurysm will die within 3 months. Those who survive may have permanent brain damage. If you have symptoms that you think may be caused by an aneurysm, see a doctor right away or go to the ER.

Are there warning signs days before an aneurysm?

If an aneurysm starts leaking before it ruptures, you may notice a warning headache. Most of the time, there is no warning.

Can stress cause an aneurysm?

Stress and your reaction to stress can lead to high blood pressure, which makes an aneurysm more likely. It's also possible that physical or emotional stress can make an aneurysm more likely to burst. 

Can an aneurysm resolve itself?

Aneurysms usually don't go away on their own. But there are documented cases of aneurysms that have gotten smaller or disappeared.